The battle for control of Hollinger International has taken a new twist after the newspaper publisher’s controlling shareholder, Hollinger Inc, warned it could face demands for the early repayment of $78m in bonds.

Trustees for the bondholders have served notice on Hollinger Inc, chaired by Conrad Black, that triggers a 30-day deadline to file delayed financial statements or face early repayment of $78m in senior secured notes, originally due in 2011.